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AbstractIn survey research sampling, the issuethat researchers are faced with is theproblem of determining an appropriatesample size. So, the researchers mustrealise that determining the sample sizeshould concern at least two reasons; 1) toestimate the proportion of the populationand 2) to estimate the population mean.The author hypothesised that both theformula used to calculate sample size byestimating the proportion of the population[28]

: 2 1 (..-.. 2556)such as Taro Yamane's formula, and theformula to calculate sample size byestimating the average population such asKrejcie and Morgans formula forquantitative researches in the pastsometimes went wrong. The resultsshowed that, in determining the samplesize using Taro Yamanes formula and R. V.Krejcie and R. W. Morgans formula, theresults of the sample size calculationswere similar since the two formulae werealike, and, in some cases, the calculationof sample size by using Taro Yamanesformula may not be appropriate if the errorof estimates and the population size weretoo small, since that could cause mistakesor inaccuracies. Accordingly, theappropriate formula to correct theproblems, namely Wonlops formula, isthus suitable for such circumstances,either the error of estimates or thepopulation size is small, that canconsequently produce errors and alter thereliability of the research.Key Word: Population, Sample, SampleSize[29]